Pressure responsive combustion control apparatus



W. L. RIEHL.

June 16, 1953 4 Sheet sSheet 1 Filed Sept. 13, 1946 W. L. RIEHL.

June 16, 1953 PRESSURE RESPONSIVE COMBUSTION CONTROL APPARATUS FiledSept. 13; 1946 4 Sheets-Sheet 2 June 16, 1953 w, L. RIEHL 2,642,128

PRESSURE RESPONSIVE COMBUSTION CONTROL APPARATUS Filed Sept. 13, 1946 v4 Sheets-Sheet 3 18 17 L E 16 Z0 June 16, 1953 W. L. RIEHL PRESSURERESPONSIVE COMBUSTION CONTROL APPARATUS Filed Sept. 15, 1946 4Sheets-Sheet 4 Patented June 16, 1953' v PRESSURE RESPONSIVE COMBUSTIONCONTROL APPARATUS William L. Rich], Rome, N. Y., assignor to Union Fork& Hoe Company poration of Ohio Columbus, Ohio, a cor- 7 ApplicationSeptember 13, 1946, Serial No. 696,735

v This invention relates to combustion control and is particularlyapplicable to the burning of fluid fuel under automatic control,

An object ofthe invention is to provide an improved combustion controlwhich will be extremely safe in operation.

Another object of the invention is to provide an improved combustioncontrol which will accurately supply fuel in accordance with the heatrequirements of the apparatus.

Another object of the invention is to provide an improved combustioncontrol which will insure automatic ignition of fuel.

Another object of the invention is to provide an improved combustioncontrol whichwill prevent the supply ofundesirable quantit es of fuelunder any of a number'of adverse fuel burning conditions.

Another object of the invention is to provide. an improved combustioncontrol-which will be extremely reliable. a 7

- Another object of the invention is to provide an improved combustioncontrol which will be composed'of few and simple parts.

Another object of the invention is to provide an improved combustioncontrol which will require a minimum amount of servicing.

Another object of the invention is to provide an improved combustioncontrol which will be compact.

Another object of the invention is to provide an improved combustioncontrol which may be easily andeconomically manufactured.

Another object of the invention is to provide an improved combustioncontrol which will be extremely positive in its operation.

Other objec'ts'will hereinafter appear.

The invention will be better understood from the description of severalpractical embodiments thereof, illustrated in the accompanying drawings,in which: j V

Figural is a somewhat diagrammatic view, partly in elevation andpartlyin section, of one form of control intended for the burning of fluid,and preferably gaseous, fuels at subatmospheric pressures;

Figures-2, 3, 4 and 5 are fragmentary sectional viewsto an enlargedscale taken on the line 7 Claims. (01.158-7) clarity of illustration,and showing the parts in;

positions they occupy during various phases of the cycle of operation ofthe apparatus;

Figure 6 is a view similar to Figure 1 showing' a second embodiment ofthe invention; and E Figure 7 is a view similar to a portion of Figure 1showing a third embodiment intended for the burning of fuel atatmospheric pressures.

Referring ,flrst to the embodiment, namely, that of Figures 1 to 5, Ihave shown a combustion system in which fuel is burned within a sealedcombustion chamber I, fuel and air being supplied to this chamber by thecontrol apparatus to be described. The products of combustion areexhausted from the combustion chamber by a pump or blower 2. driven by amotor 3, so that the pressure within the combustion chamber ismaintained at all timesbelow that of the atmosphere.

Fuel is supplied from any source of fuel fluid under a pressure greaterthan atmospheric, such as the pipe or conduit 4, which, for the purposeof my present description, may be considered as connected to an ordinarycity gas line.

The fuel passes'through a gas pressure regulator at 5, which may be ofany well known.

upper and lower sides and having a perforation.

l2 extending to the exterior of the valve, beyond which it is providedwith a fitting [3 connecting.

it to a pipe'or tube I 4.

The topof the valve bodyis provided with.

an enlarged boss 1 5 into which is-received the lower end of a casing I6carrying an-eleotro-,

'magnet I! provided with a U-shaped core I 8. Through the bottom of thecasing [6 extends a valve stem l9 having its upper end, head or armature20 in alignment with the poles of the core [8, while the lowerend of thestem is provided with valve 2| carrying packing 22.

A spring 23 is interposed between the valve. at 22 and-the casing .16. IIt will be understood that the casing I8 is fixed to and seals the topof the valve body.

against the passage of fuel therethrough.

, The bottom of the valve body has a depend-' 'ing boss 24 which isbored for the reception of a plunger 25 which has an upper end ofreduced diameter shown as carrying a valve head 21 provided with packing28. The valve stem 26 is slidable through the valve head 21 and isprovided with a flange or collar 29 adjacent its upper end which limitsthe upward motion of the valve relative the stem. 7

Normally holding the valve head against the flange 29 is a spring 3|betweenthe upper end of the larger diametric part of plunger 25 and thelower side of the valve head.

The lower end of the plunger is provided with a roller 32 which travelson a cam 33, which will be described more fully hereinafter.

From the valve 9 the fuel passes through a pipe or conduit 34 to anorifice plate 35 secured at the end of pipe 34 as by an elbow or otherfitting 36 and constituting the main burner orifice of the apparatus.

From the fitting 35 a pipe or conduit 31 extends to the main burner 38within the combustion chamber. A branch 39 connected to conduit 3] isprovided with a manually adjustable regulating valve 40 which controlsthe ad-, mission of air to support combustion, this air being drawn inthrough the valve by the subatmospheric pressure within the pipe 31.

Connected to pipe 34, as by a nipple 4|, is a casing consisting of a top42 and bottom 43 between which is clamped a diaphragm 44., the two partsof the casing being secured together in any desired manner, as by bolts45.

The diaphragm is provided with a plate 46 having a depending stem or pin47 arranged to actuate a normally open switch 48.

Tube l4 ends at an electrically operated valve 49, from which a tube 50passes to a pilot burner 5| within the combustion chamber l adjacent theoutlet of main burner 38.

Arranged adjacent the pilot burner is an igniting spark gap, consisting'of an electrode 52 insulated from but passing through the combustionchamber wall, as by means of insulating bushings 52a, and a groundedelectrode 53.

7 Also positioned adjacent the pilot burner and the main burner, whereit will be subjected to flame from either or both, is a thermocouple 54.

A pipe 55 communicates with the interior of the. combustion chamber andis connected by fittings, such as a T 56 and nipple 57, to a casingconsisting of a cover 58 and a bottom 59 between the edges of which isclamped the edge of a diaphragm 6| the casing sections being heldtogether by bolts 6|. The diaphragm 60 has a pressure plate 6| on itsupper surface having a depending pin 62 by which it may actuate a switch63.

Passing upwardly from the pressure plate within the T 55 is acompression sprin 64, the tension of which may be adjusted by a screwplug E5 threaded in the upper branch of the T.

Connected to rotate the cam 33 is a motor 65, and positioned adjacentthe cam is aswitch 81, having an arm 68, which may be moved to operatethe switch by a projecting cam 69 formed on the side of cam 33.

A relay comprising a coil 10, an armature H and contacts 12 ispositioned adjacent the casing l6 and valve 9 and motor 55, so thatthese parts, together with switch 67, may all conveniently be enclosedin a box or cover 13.

Covers or boxes 14 and [5 also conveniently may be provided forenclosing and protecting switches 48 and 63, respectively.

A transformer is shown at 6 to furnish current at suitable potential forthe spark gap.

At i1 is shown a thermostat, which is positioned in the room or otherspace which it is desired to maintain at a uniform temperature.

Passing now to the description of the electrical circuits which areassociated with the mechanical parts above described, power is suppliedby any suitable source such as a central power house generator 18through line 19 and 80.

Line 19 includes motor 3 and thermostat 1! and terminates at switch 63.

Line 88 has four branches, one of which 89a terminates at transformer16, another 801) at switch 48, a third 890 at relay coil 70 and a fourth8003 at electro-magnetic switch 49.

From the opposite side of switch 63, a conductor 8| extends to switch61, and from switch 6? a conductor 82 extends to transformer 16.

Branching from conductor 8| is a conductor 85a which connects with theother end of coil Til of the relay, and which has a branch Blb connectedto the other side of valve 49.

Another branch 8|c connects with motor 66, While the opposite side ofthe motor is connected by a conductor 83 to switch 48.

Switch 48 is normally open, and is closed only when the vacuum withinpipe 34 is sufii: cient to raise diaphragm 44.

I Switch 63' is normally closed, and is opened only in the event of anextremely high vacuum which causes the diaphragm SEi-to overcome thepressure of spring 64.

From the secondary of transformer 16, conductors 84 and 85 pass,respectively, to electrode 52 and to the ground.

With the parts as above described; and the apparatus at rest, let it beassumed that the temperature at thermostat TI falls below the setting ofthis thermostat.

This, of course, closes the contacts of the thermostat and permitscurrent to be supplied through line 19 to motor 3, driving blower 2, thecurrent flowing through switch 63, conductors 8|, 8|a, 800, Mb, d, and80 back to the generator, thus energizing the coil 10 of the relay toclose contacts 12 and opening valve 49, current to the valve. beingsupplied to it through conductors 8|d and BI!) which connect it inparallel with the coil 10.

The closing of the contacts I2 establishes communication throughconductors and 86 between the thermo-couple 54' and coil while theopening of the valve 49 permits pilot gas to pass through pipes I4 andSite the pilot burner 5|.

At the time this is taking place, the cam 33 is in the position shown inFigures 1 and 2, where the roller 32 is at its lowermost position withvalve 21 open and valve 2| closed.

As soon as pump 2 has exhausted the contents of combustion chambersufficiently to raise diaphragm 44, switch 48 closes and current cannowpass through this switch between co'nductors 83 and 891), thus supplyincurrent to motor 66 which starts to rotate and to move cam 33.

This cam rotates in a clockwise direction, as seen in Figures 2 to .5,so that the roller for a short period is free of the cam while thelatter passes through the sector marked 33a, and thereafter climbs uponthe sector 33b to the position shown in Figure 3 where both valves 2|and 21 are closed. The succeeding sector of the cam is a dwell,indicated at 330, which may be for a substantial period, such as about aquarter of a minute, permitting the blower to completely purge thecombustion chamber of any unburned fuel.

Passing beyond the dwell of sector 33c, sector 33d of the cam againraises plunger 25, as shown in Figure 4, so that valve 2| is openedwhile valve 21 is held closed. .This. permits gas to flow from theintake side .of valve body ID to port 12, and thence through tubes l4and I 5 to the pilot burn- While'cam 33 is moving its sector 3311 underthe roller 32, its cam lug 69 engages switch arm 88 and as this'lugextends axially a sufiicient distance to actuate switch 6! thisengagement closes the switch 61, permitting current to bow through 82 tothe primary of transformer 76, and thus inducing a high tension currentin conductors 84 and 85 producing a spark between electrodes 52 and 53.

.This spark is of suflicient intensity to ignite the pilot gas, which isnow entering through the pilot burner 5|.

Continued rotation of motor 66 carries cam 33 beyond the dwell 33c,allowing the plunger to slide down the last sector 33 to the positionshown in Figure 5.

Of course, when the parts are brought into the position shown in Figure4, armature 20 is brought into contact with the poles of core [8, and ifignition of the gas has taken place within'the combustion chamber, coilI! is energized by the thermocouple and holds this armature in a raisedposition as shown in Figure 5, keeping valve 2| above its seat.

The dropping of plunger 25, of course, moves valve 21 below its seat sothat valve 9 is fully It will beobserved that the control above de-'scribed operates automatically to render the apparatus safe against theundesired supply of fuel in the event of various types of failure.

Pressure in pipe 34 opens switch 48 preventing the motor 66 from causingthe parts to go through their cycle until a proper vacuum has beenproduced.

Interruption of electric current, whether by operation of thermostat 71or from other causes, causes magnetic valve 49 to snap shut instantlystopping any supply of pilot gas.

Immediately upon exhaustion of the gas burning at the main burner,de-energization of coil I! permits valve 2! to snap shut, cutting offall fuel to the main burner as well as to the pilot burner.

Absence of flame in the combustion chamber for any reason de-energizescoil I! and closes valve 2|.

Failure of vacuum-like pressure in pipe 34 breaks the motor circuit atswitch 48.

If the pilot burner is not lit on the first cycle of the apparatus, butproper conditions of vacuum continue, the apparatus will re-cycle untilignition takes place.

Thus the control illustrated will guard against many types of failureand dangerous conditions which might arise as pointed out above.

In Figure 6, the electrically operated valve M9 has been inserted inconduit I 88 instead of between tube parts H4 and I53. The operation ofthe deviceis otherwise just as above described.

Of course with valve I49 as shown in this figure, deenergization thereofshuts off the entire gas supply, not merely that to the pilot burner.

In Figure 7 the apparatus is shown as adapted to burning fuel atatmospheric pressure. In this form, the pipe 234 terminates at thefrustro-conical end 240 of the pipe 231 leading to the main burner, thetwo pipes forming an inspirator or injector-like structure for drawingin air to support combustion at the burner.

The branch MI is provided with an apertured plate 235, through which theextension communicates with the interior of the casing con-. sisting ofhalves 242 and 243.

Within the casing is a diaphragm 244 having a rod or pin 24'! arranged,when the diaphragm is raised, to contact the arm of switch 248, thisswitch being normally open and closed only when engaged by the shank241.

It will be seen that the actuation of this switch is precisely'the sameas that of switch 48 of Figure 1, excepting that in the first figure theswitch is controlled by vacuum created by the blower:

modifications and variations coming within the scope of the appendedclaims.

I claim:

1. Combustion control apparatus comprising a combustion chamber, aburner in the chamber,

a fuel supply line leading to the burner, a valvein said line, arestricting member in the line between the valve and burner, and valvecontrol means operabl associated with the valve and controlled by thepressure in the line between the valve and restricting member.

2. Combustion control apparatus comprising a combustion chamber, aburner in the chamber, a fuel supply line leading to the burner andincluding a valve, a restricting member in said supply line between thevalve and burner, actuating means connected to said valve, control meansfor said valve connected to and responsive to the pressure in thechamber, and retaining means for said valve controlled by the existenceor absence of a flame at the burner.

3. Combustion control apparatus comprising a combustion chamber, aburner therein, a fuel supply line leading to the burner and including avalve, a restricting memberin said supply line between the valve andburner, actuating means for said valve connected to and responsive tothe pressure in the chamber, and retaining means for said actuatingmeans controlled by the existence or absence of a flame at the burner,and operating means for said valve controlled by the pressure in theconduit between the valve and the restricting member.

4. In a combustion apparatus comprising a combustion chamber, gasexhausting means connected with said chamber, a main burner and a nectedto said valve, and a pressure operated control connected to saidactuating means controlled by the pressure in said conduit betweenthe-valve and the combustion chamber.

5. Combustion control apparatus comprising a combustion chamber, aburner therein, a source of fuel under pressure, a conduit leading fromsaid source of fuel to said burner, a valve in the conduit, arestricting member in the conduit between the valve and the burner, anelectric motor, power transmission means connected thereto and arrangedto open said valve, resilient valve closing means, electro-magneticvalve retaining means arranged to hold the valve open, a pressureresponsive control connected to and actuated by the pressure in theconduit between the valve and the restricting member and controllingsaid valve retaining means, a pressure responsive controlling meansconnected to and responsive to the pressure in the combustion chambercontrolling the motor, and a thermocouple adjacent the burnercontrolling the valve retaining means.

6. Combustion control apparatus comprising a combustion chamber, aburner therein, a source of fuel under pressure, a conduit leading fromsaid source of fuel to said burner, a valve in the conduit, 3,restricting member in the conduit between the valve and the burner, anelectric motor, power transmission thereto and arranged to open saidvalve, resilient valve closing means, electro-inagnetic valve retainingmeans arranged to hold the valve open, a pressure responsive controlconnected to and actuated by the pressure in the conduit between thevalve and the restricting member and controlling said valve retainingmeans, a pressure responsive controlling means connected to andresponsive to the pressure in the combustion chamber controlling themotor, and a thermocouple adjacent the burner controlling the valveretaining means, a second conduit from the fuel supply conduitterminating in a pilot burner admeans connected 8 jacent the firstmentioned burner, and a valve in saidsecond mentioned conduit actuatedby said motor.

7. In a combustion apparatus comprising a combustion chamber, gasexhausting means connected with said chamber, a main burner and a pilotburner within the chamber adjacent each other, a source of fluid fuelunder pressure, conduit means leading from said source of fuel to saidmain burner and having successively interposed therein a valve and aconduit restricting member and an air inlet, the valve being closest thesource of fuel and the air inlet closest the main burner, electricalactuating means connected to said valve, and a pressure operated control connected to said actuating means controlled by thepressure in saidconduit between the valve and the conduit restricting member.

WILLIAM L. RIEHL.

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